Model 2241-2

This instrument is a general purpose, digital ratemeter with a built-in scaler that provides timed counts over a user specified period. This system will store detector setup information for up to two detectors so personnel can easily change detectors in the field. The LCD presents readings in a four-digit moving decimal format together with one of a wide range of available units of measure and is accompanied by several operational and alert icons. The LCD backlight can be activated and remains lit for a user-adjustable interval. This instrument features adjustable alert & alarm setpoints for both the Ratemeter and Scaler modes. Front-panel controls include a rotary switch for selecting between Off, Ratemeter Mode, and Scaler Mode, switches for audio on/off and fast/variable response time, and push buttons for activating the LCD backlight for either resetting the counts or acknowledging any alarms. A locking toggle switch facilitates swapping detectors while preventing accidental switching.

Key Features

Digital ratemeter with built-in scaler

Auto ranging

Panel mounted locking switch for selecting 2 detector setups

Adjustable alarms

Wide range HV

Overrange & overload protection

INDICATED USE: general purpose survey, gross counting

SUGGESTED DETECTORS: GM, proportional, scintillation

LINEARTY: Readings are within 10% of true value with a detector connected.

The following parameters are adjusted for each detector by a removable switchboard. Once initial setup and calibration have been completed, the switchboard can be removed without affecting normal operation of the instrument.

Variable: Dependent on number of counts present. Typical times are FAST 4 to 25 seconds, SLOW 4 to 60 seconds (All times stated from 10% to 90% of final reading)

Fixed: The parameter is adjustable from 10 to 25 resulting in a FAST response from approximately 2 to 50 seconds. The SLOW response is approximately 10 to 250 seconds. For MDA-type measurements, the fixed response mode is recommended

RATEMETER ALERT/ALARM: set at any value within the effective range of each detector

SCALER ALARM: adjustable from 1–999999 counts

SCALER COUNT TIME: adjustable from 1–9999 seconds

TEMPERATURE RANGE: -20 to 50 °C (-4 to 122 °F)

RS-232 OUTPUT OPTION: Part No. 4408-192: This option requires a firmware change on the instrument to output ASCII data.